 /*******************************************************************************
  * Copyright (c) 2000, 2006 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.core.internal.resources;

 import java.io.*;
 import org.eclipse.core.internal.localstore.IHistoryStore;
 import org.eclipse.core.internal.utils.Messages;
 import org.eclipse.core.internal.utils.UniversalUniqueIdentifier;
 import org.eclipse.core.resources.*;
 import org.eclipse.core.runtime.*;
 import org.eclipse.core.runtime.content.IContentDescription;
 import org.eclipse.core.runtime.content.IContentTypeManager;
 import org.eclipse.osgi.util.NLS;

 public class FileState extends PlatformObject implements IFileState {
     private static final IWorkspace workspace = ResourcesPlugin.getWorkspace();
     protected long lastModified;
     protected UniversalUniqueIdentifier uuid;
     protected IHistoryStore store;
     protected IPath fullPath;

     public FileState(IHistoryStore store, IPath fullPath, long lastModified, UniversalUniqueIdentifier uuid) {
         this.store = store;
         this.lastModified = lastModified;
         this.uuid = uuid;
         this.fullPath = fullPath;
     }

     /* (non-Javadoc)
      * @see IFileState#exists()
      */
     public boolean exists() {
         return store.exists(this);
     }

     /* (non-Javadoc)
      * @see org.eclipse.core.resources.IEncodedStorage#getCharset()
      */
     public String getCharset() throws CoreException {
         // if there is an existing file at this state's path, use the encoding of that file
 IResource file = workspace.getRoot().findMember(fullPath);
         if (file != null && file.getType() == IResource.FILE)
             return ((IFile)file).getCharset();
         
         // tries to obtain a description for the file contents
 IContentTypeManager contentTypeManager = Platform.getContentTypeManager();
         InputStream contents = new BufferedInputStream(getContents());
         boolean failed = false;
         try {
             IContentDescription description = contentTypeManager.getDescriptionFor(contents, getName(), new QualifiedName[] {IContentDescription.CHARSET});
             return description == null ? null : description.getCharset();
         } catch (IOException e) {
             failed = true;
             String message = NLS.bind(Messages.history_errorContentDescription, getFullPath());
             throw new ResourceException(IResourceStatus.FAILED_DESCRIBING_CONTENTS, getFullPath(), message, e);
         } finally {
             try {
                 contents.close();
             } catch (IOException e) {
                 if (!failed) {
                     String message = NLS.bind(Messages.history_errorContentDescription, getFullPath());
                     throw new ResourceException(IResourceStatus.FAILED_DESCRIBING_CONTENTS, getFullPath(), message, e);
                 }
             }
         }
     }

     /* (non-Javadoc)
      * @see IFileState#getContents()
      */
     public InputStream getContents() throws CoreException {
         return store.getContents(this);
     }

     /* (non-Javadoc)
      * @see IFileState#getFullPath()
      */
     public IPath getFullPath() {
         return fullPath;
     }

     /* (non-Javadoc)
      * @see IFileState#getModificationTime()
      */
     public long getModificationTime() {
         return lastModified;
     }

     /* (non-Javadoc)
      * @see IFileState#getName()
      */
     public String getName() {
         return fullPath.lastSegment();
     }

     public UniversalUniqueIdentifier getUUID() {
         return uuid;
     }

     /* (non-Javadoc)
      * @see IFileState#isReadOnly()
      */
     public boolean isReadOnly() {
         return true;
     }

     /**
      * Returns a string representation of this object. Used for debug only.
      */
     public String toString() {
         StringBuffer s = new StringBuffer ();
         s.append("FileState(uuid: "); //$NON-NLS-1$
 s.append(uuid.toString());
         s.append(", lastModified: "); //$NON-NLS-1$
 s.append(lastModified);
         s.append(", path: "); //$NON-NLS-1$
 s.append(fullPath);
         s.append(')');
         return s.toString();
     }
 }

